Beginning January 1, 2021, the new Centers for Medicare and Medicaid Services (“CMS”) Evaluation and Management (“E/M”) guidelines will take effect for Office and Other Outpatient codes *99202-99205 and 99212-99215. Assignment of these codes will now be determined based on medical decision making (“MDM”) or time. The need for an extended history and / or exam to support code assignment is eliminated. The documentation of an appropriate history and examination is left to the performing provider’s judgement. In this article, a comparison of the old vs. new guidelines for establishing medical decision making will be discussed, compared, and contrasted. The PDF file is the American Medical Association’s table for reference.